work towards release v0.9.3

* Added GnuPG and plugin information to about page
* Made plugin variable adjustments for webpg-npapi v0.6.4
* Moved to webpg-npapi v0.6.4
* Improved information displayed on error page
* Added parsing of PGP data in GMAIL messages
* Improved Signing of GMAIL messages in richtext and plaintext modes
* Improved parsing of PGP blocks not in a pre element
* Removed redundant iframe MutationObservers
* Added export method to WebPG textarea toolbar
* Removed HREF properties from links within webpg_results
* Added option for defining non-default GPGCONF binary location
* Removed references to (now included) libgpgme
* Added visual cue for verifying inline results
* Improved actions for outgoing messages in Thunderbird
* Added parsing of PGP data in received messages in Thunderbird
* Fixed icons in results frame for Seamonkey
* Fixed options page display issues in OSX
* Drank a beer